The present invention relates to an apparatus for separating a mixture into solid and liquid components and, more particularly, to a separating apparatus which includes a filter permeable to the liquid component against which the mixture is urged to separate the liquid component. The solid component is subsequently scraped from the filter wall.
Separating devices of this type are known, generally, as for example as shown in Dutch Patent No. 148,242 which is directed in particular to equipment for freezing a solvent out of a solution.
In this kind of freeze concentrating equipment, which is used, for example, to freeze concentrate beverages and to purify chemicals and the like, a rotating circular-cylindrical filter is mounted within a separating tank so that one end of the interior space defined by the filter is placed in communication with the tank outlet. The mixture is then urged under pressure against the outer surface of the filter. The solid components remain on the outside surface of the filter, within the tank, while the liquid component passes through the filter and to the outlet of the tank. The solid components which collect on the outer surface of the filter are then scraped off by a stationary scraper as the circular-cylindrical filter rotates.
However, because the scraper does not positively urge the solid material toward and into the mixture within the tank, the cake of solid components which has been scraped off the filter wall in this device must be reintroduced into the mixture during the concentrating process. Indeed, the solid material will tend to collect adjacent the scraper since little or no influence can be made on the reintroduction of the filter cake scraped off.